Reenforced propeller blade end



Dec. 8, 1931.

'T. A. DICKS REENFORCED PROPELLER BLADE END Filed Sept. 19, 1929 INVENTOPatented Dec. 8, 1931 UNITED STATES PATENT OFFICE THOMAS A. DIOKS, O1PITTSBURGH, PENNSYLVANIA, ASBIGNOR TO PITTSBURGH SCREW AND BOLTCORPORATION, 01 PITTSBURGH, PENNSYLVANIA, A CORPORATION OF PENNSYLVANIAREENZB'OROED PROPELLER BLADE END Application filed September 19, 1989.Serial No. 883,678.

This invention relates to propeller blade ends and more particularly totubular propeller blade ends which are inserted into hubs containingangular sockets for the reception of the blade ends and wherein theblade ends are strengthened so as to rovide a strong eflicientconnection with the ub socket.

As I have disclosed in other of my applications it is customary torovide a hub aving 1o angularly disposed soc ets therearound for thereception of the ends of thepropeller blades such .as those used foraeronautical purposes or for other similar or analogous purposes. Inthese other inventions I have strengthened the connection between theropeller blade end and its'socket by wel ing metallic inserts to theinterior surfaces of the propeller blade end at diametrically oppositepoints thereof, but I have found that it is somewhat diflicult andinconvenient to make these welds as they are comparatively inaccessibleand hence difiicult to finish smoothly and properly. The strength of theweld is, therefore, not as great as might be obtained were the weldperformed in a more accessible location and hence the speed with whichthe welds can be completed is relatively slow and thus the costincreased.

It is an object of the present invention, therefore, to strengthen theconnection between the propeller blade end and the hnb socket in a moreaccessible and inexpensive manner.

It is another object of the present invention to make the reenforcementon them:- terior surface of the propeller blade' end rather than on theinterior surface.

It is a further object of the invention to flatten or depress suitableand preferably diametrically opposite portions of the propeller bladeend and to use the depressions thereby formed in which to accomplish thereenforcement.

Other and further objects of the invention will either be apparenthereinafter or will be pointed out as the description proceeds.

I have illustrated two forms of my invention in the accompanyingdrawings where- Fi re 1 is a plan view of the end of the tubu arpropeller blade.

Fig. 2 is a section on the line II-II of Fi 1. A

ig. 3 is a section on the line III-III of Fig. 1 and; I

ig. 4 is a view similar to Fig. 3 of a modified form of the invention.

Similar numerals refer to similar parts depth of the depressions issubstantially the thickness of the wall 11 of the ropeller blade,although the exact depth of the depressions can be suitably adjusted ordeter-.

mined according to the reenforcement required and any othercircumstances affecting 9r llmiting the various sizes and proportionsinvolved.

The form and shape of the flattened or depressed portions is clearlyunderstood by a reference to Figs. 2 and 3 and from which 1t will beseen that each depression has a flat floor 12 and inclined or slopinwalls 13 the whole dc ression bein relatively shallow and, as siown,approximately the depth of the blade wall 11. In the form shown, it isapparent that two such depressions have been formedat diametricallyopposite points and centrally of each depression is a pol gonal aperture14 through which a cross boit (not s own) passes when the blade end isinserted into the socket of a suitable hub (also not shown).

In order to reenforce the shank end at the portions where thedepressions are made, since the cross bolt passes therethrough andrequires reenforcement at those points, a reenforcing metal insert 15fol-each depression is provided which has a flattened bottom 16, but theupper surface 17 of which is contoured or configured so that it, atleast in part, restores the original outline of the blade is circular,but it is clear that an insert of any other suitable or required shapemight be equally well used. As will be noted the metal inserts aresmallerthan the depressions formed andgenerally fill upsubstantially'only the central and deepest portion of the depressions,leaving around the metal inserts a substantially triangular groove,which is thereuponfilled by weld or solder 18 in order to' completelyrestore the-original con- .tour to the exteriorsurface of the blade endat the depressed portions. This weld 18 firmly and completely unites allthecontiguous portions and the result is that the finished propeller.blade end is stronger and more unitary than ever and hence a greatlystrengthened end is provided. The apertures 14 in the depressions'andthose 19 in the metal inserts are congruent and register completely andsmoothly so -that a crossbolt can be inserted as if in, an unchangedblade end.

Since the operations are carried out on the exterior surface of theblade end instead of on theinterior surface the work can beeconomically, speedily and perfectly performed, giving a smooth, firmconstruction, which is rlgid and which will completely fulfill thefunctions for which it was designed.

It clear that the size and shape ofthe metal inserts 15 may beproportioned and contoured as found most efiicient and satis' factoryand it may be desirable to form the msert with the sides thereofinclined rather than straight. as shown, and such incline may be ineither direction so that the largest'circumference will occur either atthe top or in the bottom surfaces, which may have-the additionalfunction and effect of holding the weld or solder 18 more firmly inposition.

In the modification shown in Fig. 4 a very s mple andvery efl"ectiveform of the invent1 0n 1s illustrated. In this modification thedepressions are formed similarly to the depressions referred to inFigures 1, 2 and '3. but instead of filling the depressions partiallywith metal inserts these depressions 1 are entirely filled with weld orsolder 20 excent, of course. the central portion which is left with anaperture 21 congruent to and registering with the apertures 14 in thefloor of the depressions. This form has the advantage of extremesimplicity and rapid accomplishment in conjunction with less ex: pense,so that'unless an .extremely strong and rigid construction is required,I may utilize the form of the invention shown in Fig. 4.

It is, of course, to be understood that all the above is intended'to beillustrative" and not limitative, and that I may still further vary andmodify the details without departing from the spirit and scope of theinvention. The size and shape of the depressions may be varied, the sizeand shape of the metal inserts may be varied and the size and shape ofthe apertures provided are variable to conform with the shape and sizeof the cross bolt to be inserted therethrough. It is further to beunderstood that the diameter of the propeller blade may be any desiredone and that the thickness of the walls is conformable to the size ofthe blade. The slope of the depression walls may be any desired or maybe under-cut by sloping them in the opposite direction to that shown.

Although I have shown all the parts as being metallic, it is possiblethat other materials could be substituted where the requirements of usepermit the same, and although I have particularly referred to theaeronautical field it is clear that the inven- 'tion may be applied tothe marine field or to any other field ofendeavor in which the aboveprinciples can be utilized to advantage.

What I claim as new and desire to secure by Letters Patent is:

1. A detachable tubular propeller blade having a shank end, providedwith transversely extending diametrically opposite exterior depressionsand metallic reenforcements in said depressions restoring the originalundepressed contour of the shank end of the blade.

2. A- tubular propeller blade shank having diametrically oppositeexterior depressions with a'flat floor and sloping sides, and a metallicreenforcement with a flat bottom in each depression, the oppositesurface of the reenforcement restoring J the original contour to atleast a portion of the depressed blade shank, the original contour beingcompleted by weld.

3. A tubular propeller blade shank havlng diametrically oppositedepressions of a depth approximately the thickness of the bladeshankwall, each depression having a flat floor and sloping sides, ametallic reenforcement in each depression having a flat bottom restingon the flat floor of the depression, the top of the reenforcement andthe added weld completely filling said de-.

pressions and restoring the original exterior sions provided with a flatfloor and sloping sides and a central aperture passing therethrough, ametal insert having a fiat bottom resting on the flat floor of thedepression,

and having a top surface contoured to complete at least in part theoriginal contour of the blade shank, the remaining space in thedepression being filled with weld, so configured on its upper surface asto complete the original exterior contour of the blade shank as itexisted before the formation of the depressions.

5. A tubular propeller blade shank having diametrically oppositeexterior depressions provided with a flat floor and sloping sides and acentral aperture passing therepression being filled with weld, soconfigured on its upper surface as to complete the original exteriorcontour of the blade shank as it existed before the formation of thedepressions, said metal insert having a central aperture congruent toand registering with the aperture in the floor of the depression.

6. A detachable tubular propeller blade having a shank end provided withtransversely extending diametrically opposite depressions and weldingmetal in said depressions for reenforcing said shank and for restoringthe undepressed contour of the shank.

7. A detachable tubular propeller blade having the shank end providedwith transversely extending oppositely disposed exterior depressions,said depressions having a flat floor, sloping side walls extendingtransversely across the shank, an aperture through the center thereofand a metallic weld in said de ressions having an aperture thereinregistering with the aperture in said depressions for reenforcing theshank end of 7 said blade.

In testimony whereof, I- have hereunto subscribed my name this 18th dayof September, 1929.

THOMAS A. DICKS.

